Latent Human Traits

 I saw an article a while back about the shape of human hearts.  People who train for strength or speed or who don't train at all tend to have round hearts, similar to what is seen in other primates like chimps.  But endurance athletes have something special: endurance training causes their hearts to grow into an elongated shape.  When, say, a runner goes out for a long jog, the elongated shape of their heart causes the heart to bounce back and forth as it beats.  The momentum of the twisting allows the heart to move more blood with less muscular effort.  In other words, humans have a latent genetic ability (to use momentum of the hearts movements to pump blood more efficiently) that is only expressed in certain environmental conditions.  

In a fantasy world, what other abilities like that might humans have?  If the interior of the fantasy world is filled with vast networks of tunnels, then maybe humans have evolved ways to survive underground, but these traits only express themselves if you spend a few years down there.  Maybe if you go deep enough into the dungeon you'll find colonies of humans with strangely large eyes, better for seeing in the dark.  And if you join them, your eyes will gradually get bigger as well.  

Anyway, instead of adding yet another fantasy species to your game, just make humans weirder.  

Why does that creature exist?

 One of the more controversial decisions Gary Gygax made in D&D was what later commentators called "Gygaxian naturalism".  This refers to portraying monsters as members of an entire species that naturally exists.  This isn't always bad, but there are alternatives.  Other people with blogs have spent a great deal of time discussing this subject already, so I decided to just make a table including all the possibilities I can think of for alternative creature origin.

Comment if you think of any more to add to the list.  One obvious possibility is aliens, but I left that out since I never include them in my games.

D8/D6: Why does that creature exist?

D10: Why is that person/creature doing evil stuff?

I came across this post a while back and found it quite in line with how I wanted my games to run.  I decided to make a convenient table of the main categories of villain motivations, to ensure villains have a nice variety of motivations.  

Anyway here it is:

D10: Why is that person/creature doing evil stuff?

1. They believe they are acting in self-defense
2. They believe it's for the greater good
3. Self-interest, they believe their needs matter more than other's do
4. They believe other people will hurt them if they don’t assert dominance first
5. To get something they desperately need
6. Pure sadism
7. They're just totally numb to suffering and don't think about what they're doing
8. Their senses are warped and they don't accurately perceive what they are doing
9. They are in pain and lashing out randomly
10. Roll twice and combine

Please comment if you can think of any more options to add to the list.